Demulsifying agent



Patented Nov. 28, 1944 UNITED STATES PATENT OFFICE-f DEMULSIFYING AGENT Boris S. de Mering, Shreveport, La.

No Drawing. Application February 22, 1943,

Serial No. 476,766

3 Claims.

" ment and/ or other causes of an unknown nature, the water and oil arrive at the surface in theform of emulsions. In order to obtain pipe line .011 from this emulsion, it is necessary, of course, to break it up into its components which is ordinarily done by subjecting it to heat in the presence of a demulsifying agent.

When crude oil is stored for some time there occurs the deposition of emulsions in the bottom of the storage tanks. These emulsions are usually more diflicuit to resolve into their components than those obtained in the well-head. Many of these emulsions are so tight that they are looked upon as waste and simply burned. In this way immense quantities of valuable oil are lost.

' Among the more common demulsifying agents which have been employed in the past are those Y containing oil soluble and water soluble sulfonic acids derived from petroleum oils and salts of such acids. These suifonic acids are produced in refinery operations as a result of the treatment of petroleum oil with sulfonic acid bodies or in some instances with fuming sulfuric acid. These sulfonic acids are classified as those which are soluble in water and those which aresoluble in oil. The two types seem to have difierent and in many respects complemental properties for demulsifying purposes. Consequently, mixtures of the two are commonly employed. Furthermore, it is common practice to neutralize these acids prior to using them and this may be done by the use of any common alkali or ammonia.

These sulfonic compounds of petroleum origin are ordinarily quite viscous and in cold weather give much trouble in handling. It has been proposed, therefore, to utilize various diluents in conjunction with these sulfonic products among which may be mentioned light petroleum distillates, alcohols and the like. Certain aromatic hydrocarbons have also been suggested for this purpose;

According to the present invention the demulsifying power and the physical properties of demu lsifying agents containing sulionic bodies of petroleum origin, either the water soluble or .proved by adding to them certain aromatic bases such as pyridine, quinoline and homologues and derivatives thereof, which includes the corresponding acids and sulfonic derivatives. One of the immediate improvements realized by the use of these addition agents is increased stability at elevated temperatures overcorresponding demulsifying agents which have been neutralized by the use of ammonia. Another advantage is that these addition agents serve not only as neutralizing agents but as diluents whereby they make possible suitable adjustments of the viscosity of the demulsifying agent for handling at 6 low temperatures. Finally, these additionagents have a marked effect on the demulsifying power of demulsifying agents of this type.

In order to illustrate the present invention reference may be made to actual operations in which a tank bottom emulsion was treated. This emulsion was resolved by mixing with it a water soluble petroleum sulfonic acid which had been neutralizedwith ammonia in a quantity of ten gallons of treating agent per 400 barrels of emulsion. The average treating temperature was 190 F. and in 48 hours the emulsion was not resolved below 4% of basic sediment and water which meant that a considerable amount of oil was still locked up in the form of emulsion. By the addition of one quart of pyridine (denaturing grade) to each five gallons of the treating agent it was possible to treat 400 barrels of the tank bottoms with five gallons of the treating agent to a basic sediment and water content of 0.2% at the same treating temperature. In other words, the addition of the pyridine more than doubled the effectiveness of the treating agent.

A similar experience was had with treating agents composed or blends of water soluble and oil soluble petroleum sulfonic acids. In each case the addition of the treating agent brought about more rapid and complete resolution of the emulsions. The chemical structure of the pyridine seems to improve the action of the blended sulfonic bodies.

It will be understood that for the practice of the present invention the crude pyridine fractions found on the market and supplied by the coal tar industry are satisfactory, these fractions ,0 containing pyridine. A satisfactory fraction is a crude fraction from coal tar having a 50% point of C. and a 90% point of C. Homologues, such as, crude quinoline fractions may be used with corresponding advantage. Derivaoil soluble type or mixtures of the two, are im- 55 tives of these two classes or compounds in which their essential structure is maintained are also contemplated as suitable addition agents due consideration being given in each instance to the solubility characteristics 01' the derivatives. In the foregoing specific example it will be observed that the emulsion treated was a tank bottom. This particular emulsion had been in storage' for over forty years and was very stable. Consequently, the chemical requirements for resolution of the emulsion were higher than are ordinarily required in connection with crude oil emulsions obtained at the well-head or those which have been in storage for only .a relatively short time. treating agents are used for these latter, more readily broken, emulsions are in general the same as the proportions in which other conventional chemicals are employed and are well known in the art.

The proper amount of pyridine or analogous compound to be used in the practice of the present invention may readily be determined by experiments which are conventionally carried out in the treatment of any emulsion. In general, it may be stated that the amount employed will lie within the limits of from about 1% to about The proportions in which the' 20% by volume of the total treating agent. Inthe usual run oi cases the amount of pyridine or analogous chemical employed will be from about 5% to 15% by volume of ,the.total treating agent.

The nature and objects of the present invention having been thus described and illustrated, what is claimed as new and useful and is desired .to be secured by Letters Patent is:

selected from the group consisting of pyridine and quinollne.

3. A demulsifying agent for water-in-oil emulsions comprising essentially a mixture of oil soluble and water soluble petroleum sulfonic bodies and containing an addition of a thinning amount of a substance selected from the group BQRIS s. m: MERING. 

